update postgresql to 18

modules/services/server/postgresql.nix

@@ -10,7 +10,7 @@
   #  imports = [ ./postgresql_upgrade.nix ];
   services.postgresql = {
     enable = true;
-    package = pkgs.postgresql_16;
+    package = pkgs.postgresql_18;
     settings = {
       max_connections = 200;
       listen_addresses = "localhost";

modules/services/server/postgresql_upgrade.nix

@@ -8,7 +8,7 @@
     (let
       # XXX specify the postgresql package you'd like to upgrade to.
       # Do not forget to list the extensions you need.
-      newPostgres = pkgs.postgresql_16.withPackages (pp: [
+      newPostgres = pkgs.postgresql_18.withPackages (pp: [
         # pp.plv8
       ]);
       cfg = config.services.postgresql;